Creating a Performance Baseline for SQL Server · PDF fileCreating a Performance Baseline for SQL Server Ron Johnson . Overview •Why bother? •What [s in it for me? •Contents

Creating a Performance Baseline for SQL Server

Ron Johnson

Overview

• Why bother?

• What’s in it for me?

• Contents of the performance baseline.

• Collecting performance baseline metrics.

• Putting it all together.

Creating a Performance Baseline for SQL Server - Copyright © 2012, Ron Johnson 2

Why Create a Performance Baseline

• Provides a quantified starting point for optimization efforts.

• Provides a point of reference for future performance comparisons.

• Documents the server.

• Provides a reference point for capacity planning.

3 Creating a Performance Baseline for SQL Server - Copyright © 2012, Ron Johnson

DEMONSTRATION The Goal


Information to Collect

• Static Server Data

• Database File Characteristics

• IO

• Memory

• Processor

• Wait Statistics

• Query Responsiveness


PerfMon, Profiler, and DMVs

• Performance Monitor (PerfMon) is provided as a Windows® Administrative tool – Exposes a vast number of system metrics.

• Dynamic Management Views (DMVs) are provided by SQL Server® (since 9.x) exposing a vast number of system metrics via T-SQL.

• Profiler is a SQL Server® performance tool providing a real-time view of SQL Server® performance.


Dynamic Management Views • Technically, the collection of objects referenced in the sys schema that I

will be referring to as DMVs are correctly known as Dynamic Management Objects (DMOs)

– Not at all like the Distributed Management Object (DMO) • DMOs are a “collection of COM objects that are designed for programming all aspects of

managing Microsoft SQL Server” [BOL] (deprecated, thankfully)

• DMVs are simply views (DMV) and table-valued functions (DMF) that operate at the server and database levels

– DMVs may be queried just like any other view or table-valued function

• DMVs expose information collected internally by the SQL Server Engine

– Some data is a “snapshot” while other data is cumulative (from last restart or counter reset)

• There’s a DMV for that!

– CLR, IO, Mirroring, Replication, Service Broker, Server Broker, Full-Text Search, Index, Transactions, SQL O/S, Resource Governor, …


Staging the Data

• Develop a standard intermediate raw data storage technique. – MS-Excel provides heterogeneous data storage and

visualization options.

• Backup and safeguard the raw data for future reference. – Keep the data organized.

• A picture is worth a thousand words. – Easily communicate performance data to users and

managers


Static Server Data

• Server hardware and configuration – Processors – Memory

• Instance configuration – Installed services – Configuration settings – Database option settings

• Uses – XP_CMDSHELL ‘SYSTEMINFO’ – SERVERPROPERTY – XP_REGREAD – SYS.CONFIGURATIONS – SYS.DATABASES

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Creating a Performance Baseline for SQL Server - Copyright © 2012, Ron Johnson

DEMONSTRATION Collecting Static Information


Database File Characteristics

• Storage management is a primary DBA responsibility.

• Data file size, growth, and storage utilization efficiency provide insight for capacity planning.

• IO latency by database and disk.

– SYSFILES

– DBCC SHOWFILESTATS

– DBCC SQLPERF (LOGSPACE)

– XP_FIXEDDRIVES

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DEMONSTRATION Collecting Database File Characteristics


Measuring IO Performance

• SQL Server®, as all DBMS, is IO intensive. – Overall performance is directly related to the performance of

the IO subsystem.

• IO performance measures the time required to read and write to a disk.

• We will use the IO-related DMVs to establish a Performance Baseline. – For more advanced performance issue resolution we might use

PerfMon and Profiler to collect the data then combine them over a time interval.

• DMV of interest – sys.dm_os_performance_counters – sys.dm_io_virtual_file_stats


DEMONSTRATION Collecting IO Metrics


Measuring Memory Performance

• SQL Server®, as all DBMS, performance is directly related to the amount of primary memory available to the process – “Hot” data resides in memory

• Important metrics for the Performance Baseline – Total Server Memory – Available Server Memory – SQL Server Memory – Page Life Expectancy (PLE) – Buffer Cache Hit Ratio – Plan Cache Hit Ratio

• DMV of interest – sys.dm_os_performance_counters


DEMONSTRATION Collecting Memory Performance Metrics


Measuring Wait Statistics

• What is SQL Server® waiting for? – Locking

• Deadlocks

– Worker – Memory – IO – Other

• CLR • Backup Processing • Parallelization

• Counter is cumulative – Collect and compare metrics over a time interval

• Clear counter with – DBCC SQLPERF (‘sys.dm_os_wait_stats’,CLEAR)

• DMVs of interest – sys.dm_os_performance_counters – sys.dm_os_wait_stats


DEMONSTRATION Collecting Wait Statistics


Measuring Processor Performance

• CPU utilization metrics – SQL Server® Processor time

– Batches per Second

– Compilations per Second

– Recompilations per Second

– Processor Affinity

• DMVs of interest – sys.dm_os_performance_counters

– sys.dm_os_wait_stats

– sys.dm_os_schedulers


DEMONSTRATION Collecting Processor Performance Metrics


Measuring Query Performance

• Profiler-included vs. custom templates

– Use the “Tuning” template for baseline

• Use SQL Server Agent to execute Profiler Trace

– Writing T-SQL trace definition

– Running trace as a recurrent job

• Collecting and analyzing the data

– DBA Performance database


DEMONSTRATION Collecting Query Performance Metrics


Bringing it all Together

• The Baseline Performance Assessment Report – Provides documentation of the current state of the server and

instance – Provides a reference point for future performance comparisons

and capacity planning – Provides a starting point for optimization efforts

• Baseline Performance Assessment is not a SQL Configuration and Performance Review (SQL-CPR®). – Not intended to replace a thorough server and instance

performance review.

• An opportunity to recommend server or instance configuration changes

• Backup and archive the raw data


Next Steps

• If it’s not broken, then it doesn’t need to be fixed.

– At least for now.

• Monitor performance regularly.

– Maintain a performance database.

• Resources

– Script may be downloaded at

http://rjssqlservernotes.wordpress.com/

– Related papers may be downloaded at

http://rjssqlservernotes.wordpress.com/papers/

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